The present invention concerns a lateral-traction roller shade with a lateral sheave in driving relation to a roller-shade shaft and with a resiliently active device that retains and clamps the shaft and that can be released by the sheave.
In known lateral-traction roller shades of this type, a bead chain is positioned around the sheave in such a way that the shade can be rolled up or down through the sheave by pulling on one cord or the other. Although the extent to which the shade can be pulled down can be adjusted continuously and although the shade is easy to operate from the side, it can be raised only by muscle power, which can be very exhausting if the shade is large.
Roller shades that can be centrally activated, by pulling a cord attached to a catch rod, are known. These known shades have a retraction spring that rewinds them, the retraction spring being mounted on a stationary interior rod. They also have ratchet locking devices. The length to which they can be pulled down cannot be continuously adjusted and the central activating cord can be blocked by curtains, flower pots, window seats, etc.